Recently, small-size electronic devices such as cellular phones, notebook personal computers, digital cameras, watches, PDA (Personal Digital Assistance), electric personal organizers, and the like are making remarkable advances and progresses. Primary batteries such as alkaline battery and a manganese battery or secondary batteries such as a nickel-cadmium battery, a nickel metal hydride battery, and a lithium-ion battery are used as the power source of the electronic devices. However, when the primary batteries and the secondary batteries are investigated from a perspective of the use efficiency of energy, the batteries are not necessarily utilized effectively. Therefore, nowadays, the fuel cells which can realize high energy use efficiency to substitute them for the primary batteries and the secondary batteries, have been studied actively (for example, refer to JP2001-93551A and JP2004-142831A).
The fuel cell comprises a fuel cell body in which the electrolyte plate is held between the fuel electrode and the oxygen electrode and a liquid cartridge which contains the liquid mixture of liquid fuel such as methanol or the like and water, and which is connected to the fuel cell body. When the liquid cartridge is emptied, the liquid cartridge can be replaced by the new cartridge. Further, there are various types of liquid cartridges, and as disclosed in JP2004-142831A, there is a liquid cartridge which comprises a residual measurement function.
Preferably, the above described liquid cartridge has a larger volume ratio of liquid which is contained inside with respect to the total volume. However, when a new function is added to the liquid cartridge, a new construction needs to be added. Therefore, a problem in which the amount of contained liquid becomes smaller accordingly is caused.
The object of the present invention is to suppress the decreasing of the liquid containing ratio with respect to the entire liquid cartridge.